Tire having beads of specified structure and assembly of rim and bearing support with same

ABSTRACT

A tire has a carcass reinforcement (1) which, when viewed in meridian  secn, is wound in each bead B about a bead wire (2) coated with a rubber mix, passing from the heel to the toe of the bead B, the upturn (10) being located in a profile (3) of rubber mix in the form of a wedge defined by two sides (31 and 32) coming from an apex A located beneath the section of the coated bead wire (2). Advantageously the upturn (10) surrounds in its entirety the contour of the profile (3), forming either a first radially inner side (32), a lateral side (30), and a final radially outer side (31) or a first radially outer side (31), a lateral side (30), and a final radially inner side (32). The tire may form with different rims J high-performance assemblies in the event of travel at low or zero pressure, permitting simple mounting of the tires and optionally of bearing supports S for the tire tread on the rims J.

BACKGROUND OF THE INVENTION

The present invention relates to a tire with radial carcassreinforcement, and more particularly to the structure of the beads ofthe tire. It also relates to an assembly, formed by a tire and a rim,which rim is either monobloc with seats which may or may not beinclined, or in several sections, some of which are mobile, and possiblyprovided with a bearing support which may or may not be removable.

A tire with radial carcass reinforcement usually comprises, in knownmanner, a reinforcing bead wire in each bead, around which bead wire thecarcass reinforcement is anchored by winding, forming an upturn. Thecharacteristics of the bead wire, taken in combination with the meridianprofile of the radially inner face of the bead and the meridian profileof the corresponding rim seat, ensure what is called the clamping of thebead on the rim. The clamping produces a certain compression of theportion of the bead between the bead wire and the bead seat, theclamping generally being brought about by a difference in the angles ofthe bead seat and the rim seat respectively, and/or by a difference inthe diameters of said seats.

When such a tire is used on a rim having flat or inclined seats, withangles which may vary from 0° to 30°, when the rim comprises a flat rimbase and a plurality of mobile parts, when the rim is monobloc with amounting groove, when the seats are inclined towards the inside ortowards the outside, the clamping value of the beads on the rim seats,which clamping is necessary for solving the problems relating to therotation on rim at the normal use pressure of the tire and formaintaining good lateral strength of the beads, becomes so great thatdifficulties are encountered in mounting such tires on their rims inpractically all cases, even sometimes with the use of mounting presses.

Although these presses are common tools which are usual for tiremanufacturers or motor vehicle manufacturers, they do not form part ofthe usual equipment of the garage mechanic who is usually approachedwhen there is a problem relating to the tire, for instance apassenger-coach tire.

SUMMARY OF THE INVENTION

In order to facilitate the mounting and the demounting of a tire on itsmounting rim while remedying the problems of rotation on the rim,precise location of the beads on the rim seats and fatigue strength ofsaid beads, the invention proposes a tire, at least one bead of whichhas a structure permitting modification of the clamping of the bead as afunction of the tension of the carcass reinforcement and in particularreinforcement thereof when the inflation pressure increases to itsnominal value.

According to the invention, a tire with radial carcass reinforcement,wound in each bead on at least one bead wire to form an upturn, ischaracterized in that, when mounted on rim and inflated to its servicepressure, its carcass reinforcement, viewed in meridian section, iswound in at least one bead about the bead wire coated with a rubber mix,passing from the heel to the toe of said bead, the upturn extending in aprofile made of rubber mix in the form of a wedge defined by two sidescoming from an apex located beneath the section of the coated bead wire,the radially outer side forming, with a line parallel to the axis ofrotation passing through said apex, an acute φ₁ angle open radiallytowards the outside, and the radially inner side forming with saidparallel line an acute angle φ₂ open radially towards the inside, therubber mix forming the profile, axially adjacent to the bead wire,having a Shore A hardness greater than the Shore A hardness(es) of therubber mixes located axially and radially above the bead wire and theprofile.

The outer contour of a tire bead is generally defined by three basicwalls:

a first rectilinear and/or curved wall, intended to come into contactand to bear laterally with and on the wall, perpendicular or virtuallyperpendicular to the axis of rotation, of an element foreign to thetire, an element which in the great majority of cases is a rim flange,axially on the outside of the rim, but which in certain cases is locatedaxially on the inside, as described in U.S. Pat. No. 5,634,993 andFrench publication No. 2,713,558,

said first wall being joined axially, on the inside or on the outside,to a wall called a bead seat, intended to come into contact and bearwith and on the rim seat; said bead seat may be inclined or not inclinedwith respect to the direction parallel to the axis of rotation, whichinclination may be positive or negative, and variable or not variable,

the bead seat then being connected, on the side opposite the first wall,to a third generally curved wall of generally perpendicular direction tothe axis of rotation, which wall is intended to come into contact,depending on the case, with the gas for inflating the tire or with thesurrounding atmosphere, and the radially inner end of the third wall maypossibly bear laterally on a stop which may be a protuberance orprotrusion arranged on the rim seat.

In known, everyday language, the portion of the bead definedsimultaneously by the first wall of the contour of the bead and by thebead seat is called the heel of the bead, whereas the portion definedsimultaneously by the third wall and by the bead seat is called the toeof the bead.

"Wedge" is intended to mean a sector defined by two rectilinear orcurvilinear sides or radii, starting from the apex or center of thesector, the two respective ends of which define a third side, oppositethe center, of any shape.

Preferably the angles φ₁ and φ₂ which are formed respectively by theradially outer and inner sides of the profile or wedge with a lineparallel to the axis of rotation are respectively between 20° and 70°and between 0° and 30°.

Advantageously, the rubber mix forming the profile or wedge, axiallyadjacent to the bead wire, will have a Shore A hardness of at least 65(measured according to ASTM standard D.67549T).

The invention has the advantage of being able to realize, in the case ofpassenger-coach tires, beads having little or no initial clamping, theradially inner face of the bead or seat being substantiallydimensionally identical to the face opposite the seat of the mountingrim of the tire. "Dimensionally identical" is intended to mean that thebead seat has the same dimensions at all points, with respect to thethree conventional coordinate axes, as the portion opposite the rimseat.

The coated bead wire, which has in meridian section a substantiallycircular section, is advantageously capable of being moved in rotationabout its mean axis, and may be a bead wire which is rigid in torsion,as is a bead wire obtained by winding a wire of quadrilateral section oras is a bead wire obtained by winding a metal band of straight or curvedmeridian section, this coated bead wire which is rigid in torsion notbeing glued to the rest of the bead. Another variant consists in coatingthe bead wire with a thin layer of vulcanized mix having a Shore Ahardness of at most 35. "Mean axis" of a bead wire is intended to meanthe circle which is the geometric locus of the centers of gravity of themeridian sections of said bead wire.

Preferably, said bead wire may be a bead wire of braided type, that isto say a bead wire formed of a core around which are wound one orseveral cords or cables on one or more layers. As is known per se, thelayer(s) of cord(s) or cable(s) are capable of turning about the core.

The bead wire reinforcing the bead is surmounted radially on the outsideby a substantially triangular profile made of a rubber mix preferablyhaving a Shore A hardness of less than 50. The space, firstly axiallyadjacent to the profile radially surmounting the bead wire, and secondlyradially adjacent to the profile or wedge axially next to the bead wire,is filled by a third profile of rubber mix substantially of triangularshape, said mix also having a Shore hardness of less than 50.

The carcass reinforcement upturn may be substantially rectilinear andhave a length substantially equal to the length of the sides of therubber profile in the form of a wedge. It may be located on the insideof the profile, one part of the profile being radially above the upturnand one part of the profile being below the upturn. This latter may formthe radially inner side of the rubber profile. Advantageously, theupturn will form the radially outer side of the profile or wedge, giventhat it is necessary to acknowledge by convention that the upturn isalso, in the above two cases, considered as extending within theprofile.

Whether the initial clamping on the rim be zero or of a given value,whether the upturn be located within the profile or wedge, on theradially outer side, or on the inner side of said profile, the axialdisplacement of the anchoring bead wire of the carcass reinforcement,which may result from the tension of said reinforcement, which tensionis due, for instance, to the inflation pressure of the tire, makespossible, in combination with the axial disposition of the rubberprofile reinforced by the upturn, to obtain clamping of the toe of thebead on the rim seat. The value of this clamping increases as a functionof the tension force to which the carcass reinforcement is subjected,and may become very great in the case of high tension, for instance whenone of the sidewalls of the tire is placed under great tension by atransverse force.

A tire in which the carcass reinforcement is wound about a bead wire,passing from the toe to the heel of the bead and such that the upturnrests partially and radially on the outside on a second bead wirelocated axially on the outside, is known from U.S. Pat. No. 3,301,303.This second bead wire, in combination with the meridian profile of theupturn, is necessary in order to avoid the unwinding of the carcassreinforcement, in particular in the case of beads damaged by heat. Thesection of the second bead wire is radially incompressible, and does notpermit radial forces to be transmitted to the rim seat.

Preferably, the carcass reinforcement upturn will have a length suchthat it will be in contact with the total perimeter of the profile orwedge; it will thus form the two radially outer and inner sides of therubber profile and the side opposite the apex or center of the profile,and its end will be located axially beyond the point of intersection ofthe two outer and inner sides. The part of the upturn immediatelyadjacent to that part of said upturn which is wound around the bead wiremay in the first instance form the radially outer edge of the profile orwedge and then the side opposite the apex of said profile, and thenfinally the radially inner side of said profile, ending beyond thejunction point of the two outer and inner sides. It may also formfirstly the radially inner side of the profile or wedge, then the sideopposite the apex of said profile, and then finally the radially outerside of said profile, ending in the same manner as previously.Advantageously, the end of the carcass reinforcement upturn will beradially further from the axis of rotation than the center of gravity ofthe section of the coated bead wire.

The invention applies whatever the inclination of the bead seat, but itis particularly beneficial in the case of seats inclined towards theoutside of the tire, the toes of the bead then being on the outside.

DESCRIPTION OF THE DRAWINGS

The invention will be better understood with reference to the drawingsappended to the description, which illustrate non-limiting examples ofembodiment of tires according to the invention and which, whenassociated with suitable rims, form high-performance tire-rimassemblies. In these drawings:

FIGS. 1, 1A, and 1B show diagrams of a tire bead, in accordance with afirst variant according to the invention and mounted on a rim seat saidto be inclined towards the outside,

FIG. 2 shows a diagram of a tire bead, in accordance with a secondvariant according to the invention and mounted on a seat identical tothe previous one,

FIG. 3 shows a tire bead in accordance with a third variant according tothe invention and mounted on a rim seat inclined towards the inside atan angle of inclination of 5°±1°,

FIG. 4 shows a diagram of an assembly formed by a tire and a so-calledmonobloc rim having seats inclined at 15°±1°,

FIG. 5 shows a diagram of an assembly formed by a tire, a monobloc rimhaving asymmetrical seats and a bearing support for the tread,

FIG. 6 shows a diagram of an assembly formed by a tire according to theinvention, a so-called three-part rim and a bearing support for thetread,

FIG. 7 shows a diagram of an assembly formed by a tire according to theinvention, a three-part rim according to a second embodiment, and abearing support,

FIG. 8 shows a variant of the assembly as shown in FIG. 7.

DESCRIPTION OF PREFERRED EMBODIMENTS

The bead B of the passenger-coach tire, shown in FIG. 1 and inaccordance with the invention, comprises a coated bead wire 2 of the"braided" type, around which a carcass reinforcement 1 is wound which inthe example illustrated is composed of a single ply of textile cables,forming an upturn 10. The meridian profile of the mean fiber of thecarcass reinforcement 1 (in dashes) is at a tangent to the coated beadwire 2 at a point T, and said tangent (TT') forms with a line parallelto the axis of rotation of the tire an angle φ, open radially andaxially towards the outside, of 85°. The contour of the bead Bcomprises, axially on the inside, a wall 440 substantially perpendicularto the axis of rotation and bearing laterally on the axially innerflange 44 of the mounting rim J. This rim is a rim as described in U.S.Pat. No. 5,634,993, that is to say, having the distinctive feature ofhaving at least one rim seat inclined towards the outside, said seatbeing extended axially on the inside either by a rim flange or by therim base on which a bearing support for the tread is placed, one lateralface of said support being used as a rim flange. The seat is extendedaxially on the outside by a protrusion or hump of low height. The wall440 of the bead B is extended axially on the outside by a frustoconicalgeneratrix 430, forming an angle γ of 45° which is open axially towardsthe inside and radially towards the outside with a line parallel to theaxis of rotation. The generatrix 430 is itself extended axially on theoutside by a second frustoconical generatrix 420 having a bead seatforming an angle α of 15° open axially towards the inside and radiallytowards the outside with the direction of the axis of rotation. Thegeneratrix is said to be inclined towards the outside, its axially outerend being on a circle of diameter less than the diameter of the circleon which its axially inner end is located. A frustoconical generatrix410, extending the generatrix 420 axially on the outside and forming anangle β of 45° open axially and radially towards the outside with thedirection of the axis of rotation, completes the contour of the base ofthe bead B. The wall 450, which is curved in the example described andis of substantially perpendicular general orientation to the directionof the axis of rotation of the rim, completes the contour of the bead B.Whereas the generatrix 420 will bear on the rim seat 42, inclinedtowards the outside, the generatrix 410 will bear on the axially innerwall of the protrusion or hump 41 of the rim J, inclined by the sameangle β as the generatrix 410. The portion of the bead adjacent to thewall 440 and to the generatrix 420 forms, viewed in meridian section,the heel of the bead B. The portion of the bead adjacent to thegeneratrix 420, to the generatrix 410 and partially to the wall 450forms the toe of the bead B. The carcass reinforcement 1 is wound aboutthe coated bead wire 2, passing from the heel to the toe of the bead B,to form an upturn 10 which is substantially rectilinear and locatedwithin a profile 3, arranged axially on the outside of the anchoringbead wire 2 of the carcass reinforcement 1. This profile 3 is in theform of a substantially circular sector with an apex or center A locatedradially below the bead wire 2, two sides or radii 31 and 32 startingfrom said apex A, and a third side 30, opposite the apex A. The side orradius 31 radially on the outside forms an angle φ₁ of 45° with a lineparallel to the axis of rotation, whereas the radially inner side orradius 32 forms an angle φ₂ of 15° with the same parallel line. Thisprofile 3, which is completed axially on the outside by thesubstantially circular side 30, is made of a rubber mix having a Shore Ahardness of 94 in the vulcanized state. The coated bead wire 2 issurmounted radially on the outside by a profile 7 of rubber mix having aShore A hardness of 37. Radially on the outside of the profile 3 andaxially on the outside of said profile 7 there is located a thirdprofile 6 made of rubber mix having a Shore A hardness equal to that ofthe profile 7 and therefor significantly less than the hardness of themix of the profile 3, which makes it possible, upon an increase intension of the carcass reinforcement, to facilitate the axialdisplacement of the braided bead wire 2 towards the outside of the beadB and thus to create a compression of the profile 3 and self-clamping ofthe toe of the bead on the mounting rim J, whereas, in the casedescribed, the initial clamping of the bead B on said rim is zero. Thebead B is completed by the protector 5. FIGS. 1A and 1B are similar toFIG. 1 but show the upturn 10 forming the radially outer side or radius31 and forming the inner side or radius 32, respectively.

FIG. 2 shows the variant of a bead according to the invention, thisvariant being characterized by the fact that the upturn 10 of thecarcass reinforcement 1 surrounds in its entirety the contour of theprofile 3, forming firstly the radially inner side 32 of the profile 3,secondly the lateral side 30 axially on the outside of said profile andfinally the radially outer edge 31 of the same profile, winding againaround the bead wire 2, the end of said upturn being located radiallyabove the bead wire 2. The end is thus advantageously shielded from theusual deformations to which the ends of carcass reinforcement upturnsare generally subjected, which deformations lead to poor fatiguestrength of the beads.

The assembly, formed by a tire according to the invention and a rim, maycomprise a rim with two identical rim seats, the axially inner ends ofwhich are located on circles of diameters greater than the diameters ofthe circles on which are located the axially outer ends, such seatsbeing shown in FIGS. 1 and 2. The tire-rim assembly may, in accordancewith another variant, comprise a rim having a first seat as definedabove and said to be inclined towards the outside and a second seat saidto be inclined towards the inside, the axially inner end of said seatbeing on a circle of diameter less than the diameter of the circle onwhich the axially outer end is located. The tire of the assemblyobviously includes beads of a shape adapted to the shape of the rimseats.

The tire-rim assembly may also comprise a rim, the two seats 42 of whichare inclined towards the inside, the axially inner end of each seat 42being located on a circle of diameter less than the diameter of thecircle on which the axially outer end is located, said seats 42 beingjoined axially on the outside to two flanges 44.

FIG. 3 shows a bead B, in accordance with a third variant according tothe invention, suitable for mounting on a rim seat 42, inclined towardsthe inside and joined axially on the outside to a rim flange 44. Theheel of the bead B is then located axially on the outside, whereas thetoe of said bead is axially on the inside, the rim flange or flanges 44then being located axially on the outside of the rim J. In the exampleillustrated, the center of the meridian section of the coated bead wire2 is located in the axially outer part of the bead B, or if the width ofthe bead B is called L, said center 0 is separated from the inner wallof the rim flange 44 by a distance of at most half L. Axially on theinside there is located the profile 3 of rubber mix, which is of thesame shape as the profiles described previously, although the angleswhich the sides or radii 31 and 32 form have been adapted to the bead inquestion. The radially outer side 31 forms an angle φ₁ of 30° with aline parallel to the axis of rotation, whereas the radially inner side32 forms an angle φ₂ of 5° with the same parallel line. The profile 3 ismade, as previously, of vulcanized rubber mix having a Shore A hardnessof 94. The profiles 6 and 7 of rubber mix which, respectively, arelocated radially on the outside of the profile 3 and radially n theoutside of the bead wire 2 are similar to the profiles 6 and 7 describedin that part of the description which relates to FIGS. 1 and 2. In thisexample, the meridian profile of the carcass reinforcement upturn isdifferent from the profiles described previously; in fact, the upturn 10of the carcass reinforcement 1 surrounds in its entirety the contour ofthe profile 3, forming firstly the radially outer side 31 of the profile3, secondly, the axially outer lateral side 30 of said profile andfinally the radially inner side 32 of the same profile, and winds againaround the bead wire 2, the end of said upturn still being locatedradially above the bead wire 2.

FIG. 4 shows an assembly formed by a tire according to the invention,mounted on its service rim. The rim J is a monobloc rim comprising rimseats 42 which are inclined towards the inside with respect to thedirection of the axis of rotation of the assembly and form an angle of15°±1° with said direction, curved A flanges 44 axially on the outsideof said seats and an assembly groove, in accordance with currentstandards. In each bead B of the tire, the upturn 10 of the carcassreinforcement 1 surrounds the profile 3 in its entirety, passing fromthe heel to the toe of the bead, the end of the upturn 10 being locatedradially above the metal bead wire 2. As in the case of FIG. 2, theupturn 10 forms firstly the radially inner side 32 of the profile 3,secondly the lateral side 30 axially on the inside of said profile andfinally the side radially on the outside 31 of the same profile, andthen winds round the bead wire 2 again, this upturn profile making itpossible to have the end of said upturn axially on the inside of themeridian profile of the carcass reinforcement and thus to improve thefatigue strength of the beads. Said strength may be improved stillfurther by the presence between the carcass reinforcement and its upturnof an additional strengthening reinforcement 9, formed of textile ormetallic cables, oriented with respect to the circumferential directionby a slight angle, which may be between 0° and 45°.

The tire/rim assembly may advantageously comprise a rim J having firstlya first seat 42', as defined above, and said to be inclined towards theoutside and secondly a second seat 42" said to be inclined towards theinside, the tire of said assembly obviously comprising beads of a shapeadapted to the shape of the rim seats 42' and 42". The two seats maythen be of equal or unequal diameters.

The rim J, which forms with a tire, according to the invention, theassembly shown in FIG. 5, is a rim such as is described, for example, inU.S. Pat. No. 5,787,950, and more precisely in the passage of thedescription of said patent relating to FIG. 3 of the appended drawings.The rim J comprises a first rim seat 42', the axially outer end of whichis on a circle of diameter less than the diameter of the circle on whichthe axially inner end is located, and a second rim seat 42", the axiallyouter end of which is located on a circle of diameter greater than thediameter on which the axially inner end is located. The two seats 42'and 42" have frustoconical generatrices forming with the axis ofrotation an angle which is identical for the two generatrices and whichis equal to 6°. The first seat 42' is extended axially on the outside bya protrusion or hump 41' of low height h₀, equal to 3.5 mm, and havingan inner frustoconical wall forming with the axis of rotation of the riman angle β' of 45°. Axially on the inside, the first rim seat 42" isjoined to a rim base 40 by means of a frustoconical generatrix, thediameter D_(N) of said cylindrical rim base being slightly greater thanthe diameter D'_(B) of the axially inner end of the seat 42', whichdiameter is itself greater than the diameter D'_(S) of the outerprotrusion 41'. The second rim seat 42" is extended axially on theoutside by a rim flange 44 having an inner wall perpendicular to theaxis of rotation and having a radially outer end, the diameter D_(R) ofwhich is the maximum diameter of the rim. Axially on the inside, thesecond rim seat 42" is extended by a protuberance 41", the height h₁ ofwhich is similar to the height of the protrusions or humps normally usedon current standardized rims. The two rim seats 42' and 42", which aredissymmetrical by the directions of inclination of their generatrices,are also dissymmetrical by their diameters, the diameter D"_(B), of theaxially inner end of the second rim seat 42" being greater than thediameter D'_(B), of the axially inner end of the first rim seat 42'. Theassembly is completed by a bearing support S for the tread, held in theaxial position firstly by one of the beads B of the tire mounted on itsrim J and secondly by a protuberance 45 located on the rim base 40, thelateral face of the bearing support being considered as the equivalentof the wall of a rim flange axially on the inside of the rim seat. Thebeads B of the tire are then adapted to such a rim configuration: in thebead B intended to be mounted on the first rim seat 42', the carcassreinforcement 1 is wound about the coated bead wire 2', according to theinvention, passing axially from the inside to the outside, since, inthis bead, the heel is on the inside, the wall of the rim flange beingadvantageously replaced by the equivalent wall of the bearing support S;in the bead B intended to be mounted on the second rim seat 42", thecarcass reinforcement 1 is wound round the coated bead wire 2", passingfrom the outside to the inside since the heel of said bead is thenaxially on the outside.

FIG. 6 shows another example of an assembly composed of a tire accordingto the invention, a rim J and a bearing support S. The rim J comprisesthree metal parts: a first part 4 formed primarily of the rim base 40,connected on one hand to a first rim seat 42' and axially on the outsideto a rim flange 44' integral with the seat 42', and comprising on theother hand the part intended to receive the second metal part 4' of therim J. Said demountable part 4' is formed by a rim seat 42" and a rimflange 44". The third part is the locking ring 4". The rim seats 42' and42" have respectively generatrices which are symmetrical with respect tothe equatorial plane of the assembly and frustoconical, forming with thedirection of the axis of rotation an angle α' of 5° open radially andaxially on the outside. The two rim flanges 44' and 44" being axially onthe outside of the two rim seats 42' and 42", the carcass reinforcement1, in each bead B, winds around the bead wire 2, passing from theoutside to the inside and then coming back beneath the bead wire 2,after having surrounded a profile 3 of rubber mix in the form of awedge, as in the examples already described. The assembly isadvantageously completed in this example by a bearing support S, themeridian section of which is substantially rectangular and the radiallyinner face of which rests on the cylindrical face of the rim base 40.The lateral sides S₁ and S₂, which are axially distant by the maximumaxial width of the support S, are in contact with the axially innerwalls of the toes of the beads B, and thus avoid the axial displacementof the beads B of the tire towards the inside in the case of travel atlow or zero pressure.

In the example described above and shown in FIG. 6, it is necessary toplace between the radially inner cylindrical face of the mobile rim seat42" and the radially outer face of the part of the corresponding rimbase 40 a gasket 46 made of vulcanized rubber, this gasket being placedin the half-grooves provided for this purpose.

The example illustrated in FIG. 7 differs from that of FIG. 6 by thefollowing characteristics: the gasket is dispensed with, the rim seat42" no longer forms part of the mobile part located on, for instance,the outer side of the assembly, the generatrix of said seat 42" havingbecome parallel to the axis of rotation and said seat 42" then beingable to form an integral part of the rim base 40, the rim flange 44"alone remaining mobile. The rim has become asymmetrical owing to thefact that its rim seat 42' has a frustoconical generatrix and that itsrim seat 42" has a generatrix parallel to the axis of rotation.

The example illustrated in FIG. 8 accentuates this asymmetry, in thesense that the rim seat 42", which still forms an integral part of therim base 40, has a generatrix formed by a frustoconical portion axiallyon the inside and over at least 75% of the axial width of the seat, theangle α" of which, with the direction parallel to the axis of rotation,is equal to 5° but open radially towards the outside and axially towardsthe inside, said frustoconical portion being extended axially on theoutside by a cylindrical generatrix. In this example, as in the previousexample, the rim seat 42' preserves a frustoconical generatrix formingan angle α' of 5° open radially and axially towards the outside with thedirection parallel to the axis of rotation. As in the examplesillustrated in FIGS. 6 and 7, the carcass reinforcement 1 winds in eachbead about the bead wire 2, passing from the heel to the toe of saidbead, and then surrounds in its entirety the profile 3 of rubber mixlocated axially on the inside of the bead wire 2.

We claim:
 1. A tire with radial carcass reinforcement, wound in eachbead B on at least one bead wire (2) to form an upturn (10), theradially inner face of each said bead being substantially dimensionallyidentical to the face of the seat of its intended mounting rim,characterized in that, when mounted on the rim and inflated to itsoperating pressure, its carcass reinforcement, viewed in meridiansection, is wound in at least one of the beads B about a bead wire (2)coated with rubber mix, passing from the heel to the toe of said atleast one bead B, the upturn (10) extending in a profile (3) made ofrubber mix in the form of a wedge defined by two sides (31 and 32)coming from an apex A located beneath the section of the coated beadwire (2), the radially outer side (31) forming, with a line parallel tothe axis of rotation passing through said apex A, an acute angle φ₁ openradially towards the outside, and the radially inner side (32) formingwith said parallel line an acute angle φ₂, open radially towards theinside, the rubber mix forming the wedge profile (3), axially adjacentto the coated bead wire (2), having a Shore A hardness of at least 65and greater than the Shore A hardness of any rubber mixes locatedaxially or radially outside the coated bead wire (2) and the wedgeprofile (3).
 2. A tire according to claim 1, characterized in that theangle φ₁ is between 20° and 70°, whereas the angle φ₂ is between 0° and30°.
 3. A tire according to claim 1, characterized in that the bead wire(2) reinforcing the bead B is surmounted radially on the outside by asubstantially triangular profile (7) made of a rubber mix having a ShoreA hardness of less than 50, the space, firstly axially adjacent to thesubstantially triangular profile (7), and secondly radially adjacent tothe wedge profile (3) axially adjacent to the coated bead wire (2),being filled by a third profile (6) of rubber mix substantially oftriangular shape, said mix also having a Shore A hardness of less than50.
 4. A tire according to claim 1, characterized in that the coatedbead wire (2), which has in meridian section a substantially circularsection, is capable of being moved in rotation about its mean axis.
 5. Atire according to claim 4, characterized in that the coated bead wire(2) is a bead wire which is rigid in torsion, coated with a thin layerof vulcanized rubber mix having a Shore A hardness of at most
 35. 6. Atire according to claim 4, characterized in that the coated bead wire(2) is formed of a core around which are wound at least one cord orcable in one or more layers.
 7. A tire according to claim 1,characterized in that the carcass reinforcement upturn (10) issubstantially rectilinear, has a length substantially equal to thelength of the sides (31 and 32) of the wedge profile (3), and forms theradially inner side (32) of the wedge profile (3).
 8. A tire accordingto claim 1, characterized in that the carcass reinforcement upturn (10)is substantially rectilinear, has a length substantially equal to thelength of the sides (31 and 32) of the wedge profile (3), and forms theradially outer side (31) of the wedge profile (3).
 9. A tire accordingto claim 1, characterized in that the carcass reinforcement upturn (10)has a length such that it is in contact with the total perimeter of thewedge profile (3) and thus forms the two radially outer and inner sides(31 and 32) of the wedge profile (3) and the lateral side (30) oppositethe apex A of said wedge profile (3), the end of said upturn (10) beinglocated axially beyond the apex A.
 10. A tire according to claim 9,characterized in that the end of the carcass reinforcement upturn (10)is radially further from the axis of rotation than the center of gravityof the section of the coated bead wire (2).
 11. A tire according toclaim 1 in which the carcass reinforcement upturn (10) forms theradially inner side (32) of the wedge profile (3) and then the lateralside (30) opposite the apex A of the wedge profile (3) and then theradially outer side (31) of the wedge profile (3).
 12. A tire accordingto claim 1, characterized in that it comprises at least one first beadB, the seat of which is inclined towards the outside, the heel of thebead being axially on the inside, whereas the toe of the bead is axiallyon the outside, and the carcass reinforcement winding around the coatedbead wire (2), passing from the inside to the outside.
 13. A tireaccording to claim 12, characterized in that it comprises a second beadB, symmetrical to the first bead with respect to the equatorial plane ofthe tire.
 14. A tire according to claim 12, characterized in that itcomprises a second bead B, the seat of which is inclined towards theinside, the heel of the bead being axially on the outside, whereas thetoe of the bead is axially on the inside, and the carcass reinforcementwinding around the coated bead wire (2), passing from the outside to theinside.
 15. A tire according to claim 1, characterized in that itcomprises at least one first bead B, the seat of which is inclinedtowards the inside, the heel of the bead being axially on the outside,whereas the toe of the bead is axially on the inside, and the carcassreinforcement winding around the coated bead wire (2), passing from theoutside to the inside.
 16. A tire according to claim 15, characterizedin that it comprises a second bead B, symmetrical to the first bead withrespect to the equatorial plane of the tire.
 17. A tire according toclaim 15, characterized in that it comprises a second bead B, the seatof which has a generatrix parallel to the axis of rotation, the heel ofthis second bead being axially on the outside and the toe of the beadbeing axially on the inside, the carcass reinforcement winding aroundthe coated bead wire (2), passing from the outside to the inside.
 18. Atire according to claim 15, characterized in that it comprises a secondhead B, the seat of which is inclined towards the outside over at least75% of its axial width, the heel of this second bead being axially onthe outside, whereas the toe of the bead is axially on the inside, andthe carcass reinforcement winding around the coated bead wire (2),passing from the outside to the inside.
 19. A tire according to claim 1,characterized in that it comprises at least one first bead B, the seatof which has a generatrix parallel to the axis of rotation, the heel ofthe bead being axially on the outside and the toe of the bead beingaxially on the inside, and the carcass reinforcement winding around thecoated bead wire (2), passing from the outside to the inside.
 20. A tireaccording to claim 1, characterized in that it comprises at least onefirst bead B, the seat of which is inclined towards the outside over atleast 75% of its axial width, the heel of the bead being axially on theoutside whereas the toe of the bead is axially on the inside, and thecarcass reinforcement winding around the coated bead wire (2), passingfrom the outside to the inside.
 21. An assembly formed of a tire, itsintended mounting rim, and a bearing support for the tire tread, saidtire mounted on said rim and having a radial carcass reinforcement,wound in each bead B on at least one bead wire (2) to form an upturn(10), the radially inner face of each said bead being substantiallydimensionally identical to the face of the seat of said rim,the tirecharacterized in that, when inflated to its operating pressure, itscarcass reinforcement, viewed in meridian section, is wound in at leastone of the beads B about a bead wire (2) coated with rubber mix, passingfrom the heel to the toe of said at least one bead B, the upturn (10)extending in a profile (3) made of rubber mix in the form of a wedgedefined by two sides (31 and 32) coming from an apex A located beneaththe section of the coated bead wire (2), the radially outer side (31)forming, with a line parallel to the axis of rotation passing throughsaid apex A, an acute angle φ₁ open radially towards the outside, andthe radially inner side (32) forming with said parallel line an acuteangle φ₂, open radially towards the inside, the rubber mix forming thewedge profile (3), axially adjacent to the coated bead wire (2), havinga Shore A hardness of at least 65 and greater than the Shore A hardnessof any rubber mixes located axially or radially outside the coated beadwire (2) and the wedge profile (3), said tire comprising a first bead B,the seat of which is inclined towards the outside, the heel of the beadbeing axially on the inside, whereas the toe of the bead is axially onthe outside, and the carcass reinforcement winding around the coatedbead wire (2), passing from the inside to the outside, and a second beadB, symmetrical to the first bead with respect to the equatorial plane ofthe tire, said rim comprising a first rim seat (42) inclined towards theoutside, said seat being extended axially on the inside by a rim flange(44) and axially on the outside by a protrusion or hump (41) of lowheight, and a second rim seat (42) inclined towards the outside, saidsecond seat being extended axially by a rim base (40) on which thebearing support for the tread is placed, one lateral face of which isused as a rim flange, and axially on the outside by a protrusion or Lump(41) of low height.
 22. An assembly formed of a tire, its intendedmounting rim, and a bearing support for the tire tread, said tiremounted on said rim and having a radial carcass reinforcement, wound ineach bead B on at least one bead wire (2) to form an upturn (10), theradially inner face of each said bead being substantially dimensionallyidentical to the face of the seat of said rim,the tire characterized inthat, when inflated to its operating pressure, its carcassreinforcement, viewed in meridian section, is wound in at least one ofthe beads B about a bead wire (2) coated with rubber mix, passing fromthe heel to the toe of said at least one bead B, the upturn (10)extending in a profile (3) made of rubber mix in the form of a wedgedefined by two sides (31 and 32) coming from an apex A located beneaththe section of the coated bead wire (2), the radially outer side (31)forming, with a line parallel to the axis of rotation passing throughsaid apex A, an acute angle φ₁ open radially towards the outside, andthe radially inner side (32) forming with said parallel line an acuteangle φ₂, open radially towards the inside, the rubber mix forming thewedge profile (3), axially adjacent to the coated bead wire (2), havinga Shore A hardness of at least 65 and greater than the Shore A hardnessof any rubber mixes located axially or radially outside the coated beadwire (2) and the wedge profile (3), said tire comprising a first bead B,the seat of which is inclined towards the outside, the heel of the beadbeing axially on the inside, whereas the toe of the bead is axially onthe outside, and the carcass reinforcement winding around the coatedbead wire (2), passing from the inside to the outside, and a second beadB, the seat of which is inclined towards the inside, the heel of thebead being axially on the outside, whereas the toe of the bead isaxially on the inside, and the carcass reinforcement winding around thecoated bead wire (2), passing from the outside to the inside, said rimcomprising a first rim seat (42') inclined towards the outside, saidseat being extended axially on the inside by a rim base (40) on whichthe bearing support for the tread is placed, one lateral face of whichis used as a rim flange, and axially on the outside by a protrusion orhump (41') of low height, and a second rim seat (42") inclined towardsthe inside, said second rim seat being extended axially on the outsideby a rim flange (44) and axially on the inside by a protuberance (41").23. An assembly formed of a tire, its intended mounting rim, and abearing support for the tire tread, said tire mounted on said rim andhaving a radial carcass reinforcement, wound in each bead B on at leastone bead wire (2) to form an upturn (10), the radially inner face ofeach said bead being substantially dimensionally identical to the faceof the seat of said rim,the tire characterized in that, when inflated toits operating pressure, its carcass reinforcement, viewed in meridiansection, is wound in at least one of the beads B about a bead wire (2)coated with rubber mix, passing from the heel to the toe of said atleast one bead B, the upturn (10) extending in a profile (3) made ofrubber mix in the form of a wedge defined by two sides (31 and 32)coming from an apex A located beneath the section of the coated beadwire (2), the radially outer side (31) forming, with a line parallel tothe axis of rotation passing through said apex A, an acute angle φ₁ openradially towards the outside, and the radially inner side (32) formingwith said parallel line an acute angle φ₂, open radially towards theinside, the rubber mix forming the wedge profile (3), axially adjacentto the coated bead wire (2), having a Shore A hardness of at least 65and greater than the Shore A hardness of any rubber mixes locatedaxially or radially outside the coated bead wire (2) and the wedgeprofile (3), said tire comprising a first bead B, the seat of which isinclined towards the inside, the heel of the bead being axially on theoutside, whereas the toe of the bead is axially on the inside, and thecarcass reinforcement winding around the coated bead wire (2), passingfrom the outside to the inside, and a second bead B, symmetrical to thefirst bead with respect to the equatorial plane of the tire, said rimformed of three parts, at least two of which are removable, andcomprising two rim seats (42', 42") inclined towards the inside, saidbearing support for the tread having a maximum axial width in contactwith the axially inner walls of the toes of the two beads B of the tire.24. An assembly formed of a tire, its intended mounting rim, and abearing support for the tire tread, said tire mounted on said rim andhaving a radial carcass reinforcement, wound in each bead B on at leastone bead wire (2) to form an upturn (10), the radially inner face ofeach said bead being substantially dimensionally identical to the faceof the seat of said rim,the tire characterized in that, when inflated toits operating pressure, its carcass reinforcement, viewed in meridiansection, is wound in at least one of the beads B about a bead wire (2)coated with rubber mix, passing from the heel to the toe of said atleast one bead B, the upturn (10) extending in a profile (3) made ofrubber mix in the form of a wedge defined by two sides (31 and 32)coming from an apex A located beneath the section of the coated beadwire (2), the radially outer side (31) forming, with a line parallel tothe axis of rotation passing through said apex A, an acute angle φ₁ openradially towards the outside, and the radially inner side (32) formingwith said parallel line an acute angle φ₂, open radially towards theinside, the rubber mix forming the wedge profile (3), axially adjacentto the coated bead wire (2), having a Shore A hardness of at least 65and greater than the Shore A hardness of any rubber mixes locatedaxially or radially outside the coated bead wire (2) and the wedgeprofile (3), said tire comprising a first bead B, the seat of which isinclined towards the inside, the heel of the bead being axially on theoutside, whereas the toe of the bead is axially on the inside, and thecarcass reinforcement winding around the coated bead wire (2), passingfrom the outside to the inside, and a second bead B, the seat of whichhas a generatrix parallel to the axis of rotation, the heel of the beadbeing axially on the outside and the toe of the bead being axially onthe inside, the carcass reinforcement winding around the coated beadwire (2), passing from the outside to the inside, said rim formed ofthree parts, at least two of which are removable, and comprising a firstrim seat (42') inclined towards the inside, said seat being extendedaxially on the outside by a rim flange (44'), and a second rim seat(42"), the generatrix of which is parallel to the axis of rotation, saidsecond rim seat being extended axially by a second rim flange (44"),said bearing support for the tread having a maximum axial width incontact with the axially inner walls of the toes of the two beads B ofthe tire.
 25. An assembly formed of a tire, its intended mounting rim,and a bearing support for the tire tread, said tire mounted on said rimand having a radial carcass reinforcement, wound in each bead B on atleast one bead wire (2) to form an upturn (10), the radially inner faceof each said bead being substantially dimensionally identical to theface of the seat of said rim,the tire characterized in that, wheninflated to its operating pressure, its carcass reinforcement, viewed inmeridian section, is wound in at least one of the beads B about a beadwire (2) coated with rubber mix, passing from the heel to the toe ofsaid at least one bead B, the upturn (10) extending in a profile (3)made of rubber mix in the form of a wedge defined by two sides (31 and32) coming from an apex A located beneath the section of the coated beadwire (2), the radially outer side (31) forming, with a line parallel tothe axis of rotation passing through said apex A, an acute angle φ₁ openradially towards the outside, and the radially inner side (32) formingwith said parallel line an acute angle φ₂, open radially towards theinside, the rubber mix forming the wedge profile (3), axially adjacentto the coated bead wire (2), having a Shore A hardness of at least 65and greater than the Shore A hardness of any rubber mixes locatedaxially or radially outside the coated bead wire (2) and the wedgeprofile (3), said tire comprising a first bead B, the seat of which isinclined towards the inside, the heel of the bead being axially on theoutside, whereas the toe of the bead is axially on the inside, and thecarcass reinforcement winding around the coated bead wire (2), passingfrom the outside to the inside, and a second bead B, the seat of whichis inclined towards the outside over at least 75% of its axial width,the heel of the bead being axially on the outside and the toe of thebead being axially on the inside, the carcass reinforcement windingaround the coated bead wire (2), passing from the outside to the inside,said rim formed of three parts, at least two of which are removable, andcomprising a first rim seat (42") inclined towards the inside, said seatbeing extended axially on the outside by a rim flange (44'), and asecond rim seat (42') inclined towards the outside over at least 75% ofits axial width, said second rim seat being extended axially on theoutside by a rim flange (44"), said bearing support for the tread havinga maximum axial width in contact with the axially inner walls of thetoes of the two beads B of the tire.